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What steps can you take to determine the melting point of a substance that sublimes before it melts?
Wiki User
∙ 13y ago
In such cases the melting point determination must be performed in a sealed capillary tube to avoid loss of sample. This can be achieved by heating the open end of the capillary tube, and with tweezers forcing it shut.
Wiki User
∙ 13y ago
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How do you determine melting point of a compound that sublimes or decomposes before melting?
You don't. You determine the sublimation point or the decomposition temperature instead. In a table of melting points, such a compound would have a temperature listed along with a notation along the lines of "subl" or "dec".
Why is the melting point of a substance is a physical property but flammability is a chemical property?
In the state of matter you can use all five senses without having to change the substance (physical property). With chemical property you are altering the substance so you are able to observe it.
What type of chage is melting ice?
Melting of ice into water is a physical change. Basically, any change that involves only the form of a substance is a physical change. In this case, the water molecules are unchanged and have the same chemical properties as before the melting occurs. The act of melting only changes (increases) the internal energy between the watermolecules resulting in a less orderly structure but does not affect the molecules themselves.
How long from the from the start of the experiment was the substance heated before all of the substance turned into a liquid?
It is impossible to tell how long from the start of the experiment it was before all of the substance turned into a liquid without more information about the experiment. Perform the experiment again and use a timer to determine the length of time required to turn the substance into a liquid through heating.
What is the melting point in degrees Celsius?
Each substance has a different melting point. That depends on what compound you're talking about: Of table salt, NaCl, it is 801 °C though of water (ice), H2O, it is 0 °C and of carbon dioxide it is even lower: -78 °C
How do you determine melting point of a compound that sublimes or decomposes before melting?
You don't. You determine the sublimation point or the decomposition temperature instead. In a table of melting points, such a compound would have a temperature listed along with a notation along the lines of "subl" or "dec".
How can a substance have no melting point or boiling point?
Example: compounds that are thermally decomposed before a supposed melting or boiling point.
What is the significance of boiling point and melting point of a substance?
Melting points and boiling points are phyical constants which means specific compounds have specific melting/boiling points. Therefore you can identify a substance if you determine the mp/bp. Also you measure the purity of a mixture using melting point tests.
Why the melting point of a substance is a physical property but flammability is a chemical property?
When a substance melts, it changes state from solid to liquid. This does not alter the substance's chemical composition, so melting point is a physical property. Flammability means burning, and when a substance burns, it reacts with oxygen to produce a new substance that was not there before. This is therefore a chemical property.
What happens if a pure substance is exactly at its melting point?
it "sweats" almost like melting plastic on a Bunsen burner, like how small droplets form just before the whole pen melts.
How do the melting point and the freezing point of a substance compare?
Both indicate the temperature at which the solid and liquid states of a substance are in equilibrium.
What happens to the temperature of naphthalene during melting?
Lab: Melting / Freezing Point of NaphthaleneObjective: In this lab, you will investigate the melting and freezing point of the substance, naphthalene (moth ball flakes). You will heat solid naphthalene and record temperature changes and examine the graph to determine the melting point of the substance. You will then cool naphthalene and record temperature changes in order to determine the Freezing point of the substance Part A: What happens to temperature as naphthalene melts?Objective: As heat is applied to liquid naphthalene, the temperature rises. As the temperature rises, the naphthalene will eventually start to melt. This lab experiment tries to answer the question: what happens to the temperature of naphthalene as it melts? In this lab, you will heat the liquid naphthalene, and record the temperature changes. You will graph the temperature changes before drawing any conclusions.Part B: Determining the freezing point of naphthaleneObjective: Freezing point is a characteristic property of matter. As heat is taken away from a liquid, the temperature of that liquid decreases as the substance begins to freeze. This lab experiment tries to answer the question: what is the freezing point of an unknown liquid (naphthalene)? In this lab, you will cool liquid naphthalene, and record the temperature changes. You will graph the temperature changes before drawing any conclusions.
Why is the melting point of a substance is a physical property but flammability is a chemical property?
In the state of matter you can use all five senses without having to change the substance (physical property). With chemical property you are altering the substance so you are able to observe it.
What type of chage is melting ice?
Melting of ice into water is a physical change. Basically, any change that involves only the form of a substance is a physical change. In this case, the water molecules are unchanged and have the same chemical properties as before the melting occurs. The act of melting only changes (increases) the internal energy between the watermolecules resulting in a less orderly structure but does not affect the molecules themselves.
What is the temperature of a substance does not change before the?
The Phase Change is complete, e.g water melting from ice phase to liquid phase or water evaporating from liquid to gas. Save
How long from the from the start of the experiment was the substance heated before all of the substance turned into a liquid?
It is impossible to tell how long from the start of the experiment it was before all of the substance turned into a liquid without more information about the experiment. Perform the experiment again and use a timer to determine the length of time required to turn the substance into a liquid through heating.
If a substace is a liquid already what would it be before the melting point?
It would be solid before it reached the melting point. If it is liquid, it has already reached the melting point.
